What is a mutating table?
What is a mutating table?
A mutating table is a table that is currently being modified by an UPDATE, DELETE, or INSERT statement, or it is a table that might need to be updated by the effects of a declarative DELETE CASCADE referential integrity constraint.
What is a mutating table error?
A mutating table error (ORA-04091) occurs when a row-level trigger tries to examine or change a table that is already undergoing change (via an INSERT, UPDATE, or DELETE statement). In particular, this error occurs when a row-level trigger attempts to read or write the table from which the trigger was fired.
How do you fix a mutating error?
Fixing the mutating table error
- First, declare an array of customer record that includes customer id and credit limit.
- Second, collect affected rows into the array in the row-level trigger.
- Third, update each affected row in the statement-level trigger.
How do I fix Ora 04091?
- ORA-04091. This is Oracle’s way of saying: you really don’t want to do that.
- Option 1. Use a VIEW . This is the preferred method.
- Option 2. Use a Materialized View . Yes, you can Fast Refresh SUM() on commit.
- Option 3. Use a TAPI (Table API). ( a Package )
- Option 4. 3-Trigger solution.
How do you avoid mutating table errors?
Don’t use triggers – The best way to avoid the mutating table error is not to use triggers. While the object-oriented Oracle provides “methods” that are associated with tables, most savvy PL/SQL developers avoid triggers unless absolutely necessary.
What is Oracle Pragma?
The PRAGMA keyword is used to signify that the remainder of the PL/SQL statement is a pragma, or directive, to the compiler. Tells the PL/SQL runtime engine to commit or roll back any changes made to the database inside the current block without affecting the main or outer transaction. …
What is mutating trigger with example?
Mutating trigger is trigger that is currently being modified by DML opertion. For eg.,You created a trigger trigger1 on table1, it should fire after update for each row. And you wrote some update statement on the same table (table1) inside the trigger .
How do you avoid mutating errors?
What happens if a trigger fails in Oracle?
Statements are atomic in Oracle (as they should be in all databases). So, after your insert, if the trigger failed – the database will look like your insert never ever happened.
What is a pragma in SQL?
Can we use commit in trigger?
Any change that a trigger does is committed with the transaction that fired the trigger. So yes, the change done inside the trigger will be committed “automatically”. You can’t commit inside a trigger anyway.
